1. Field of the Invention
The present invention relates to a magnetic head and a method of manufacturing the same, and more specifically, it relates to a rotary type magnetic head mounted in systems, such as VCR, R-DAT and digital VCR and the like, and a method of manufacturing the same.
2. Description of the Related Art
In recent years, as magnetic recording technology advances in developing further high-density and wide-band recording, a high coercive force medium such as metal-particulate tape and the like has come to be a recording medium. Accordingly, for a core material of a magnetic head, thin film of soft magnetic alloy having a high saturation magnetic flux density is employed. With reference to the drawings, for example, a magnetic head 21 having a configuration where a soft magnetic alloy thin film 22 is sandwiched by nonmagnetic material 23 as shown in FIG. 15 is proposed, and another example having a configuration where a thickness of a core of a magnetic head in a front gap is made the same as required for a track width while thicknesses in any other parts are made larger in order to enhance a core efficiency.
The inventor of the present invention and his coworkers proposed a magnetic head disclosed in Japanese Unexamined Patent Publication Heisei No. 1-33709 and also proposed a method of manufacturing such a magnetic head. That is, a magnetic core is made thinner only in a region of which track width in the magnetic head is determined by directional particles as in ion milling.
FIG. 16 shows a magnetic head 24 disclosed in the same Japanese Unexamined Patent Publication Heisei No. 1-33709. Referring to FIG. 16, a thin film 26 consisting of soft magnetic thin films or a combination of soft magnetic thin films and insulating thin films has a thickness corresponding to a track width in a gap region 25 while it is thicker in any other part. The magnetic core 26 having such a configuration is made large in sectional area of a magnetic core so as to enhance a core efficiency by reducing magnetic reluctance of the core.
FIG. 17 is a perspective view of two halved bodies of the magnetic head 24 where it is divided into two between its gap facing planes so that resultant gap facing planes can be observed. Assuming that an ideal process accuracy can be attained, and even if thereby only a magnetic core 26 in a part (front gap) 29 on which a recording medium is to slide in the eventual magnetic head 24 is made thin in the method also disclosed in Japanese Unexamined Patent Publication Heisei No. 1-33709 as noted above, a pair of halves 31 of the magnetic head 24 have their respective magnetic cores 26 opposed to each other in merely a width C which is equivalent to the thickness of the core in the front gap 29 shown in FIG. 17 in the gap facing plane where the pair of halves of the magnetic head 24 are bonded together. In other words, although the magnetic core in a back gap 30 is thickened to and a magnetic reluctance is accordingly reduced to enhance a core efficiency of the magnetic head 24, an area of a cross-section of the magnetic core in the back gap 30 is made smaller causing larger magnetic reluctance, and consequently, there arises the problem that an effect of sufficient enhancement of a core efficiency cannot be obtained.